package callBack;

public class CallBackDemo {
	public static void main(String[] args) {
		A a=new A();
		a.start();
	}
}
class A{
	public void start(){
		System.out.println("start");
		B b=new B();
		b.call(this,"good");
	}
	public void callBack(){
		System.out.println("callBack");
	}
}
class B{
	public void call(A a,String good){
		System.out.println("call");
		a.callBack();
	}
}
